Millstone, KY has a population of 34 and is the 28,510th largest city in the United States. The population density is 159 per sq mi which is 47% higher than the Kentucky average and 75% higher than the national average. The median age in Millstone is 52 which is approximately 34% higher than the Kentucky average of 39. In Millstone, 74% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 74% of Millstone residents were born in Kentucky, 26% were born out of state, 0% were born outside of the United States and 0% were foreign born.